A Medical Device Daily

Research presented this week at the 32nd annual scientific meeting of the Society of Interventional Radiology (SIR; Fairfax, Virginia) in Seattle, shows that angioplasty and stenting can prevent amputation and restore blood flow in the lower extremities of patients with severe critical limb ischemia and gangrene.

At 18 months, the tiny arteries below the knee remained open, with a 91% success rate, thus preventing amputation. That success rate was consistent in all patients who were consecutively enrolled over a six-year period of time.

The blockages were caused by peripheral arterial disease (PAD), “hardening of the arteries,” the same disease which can lead to heart attack and stroke.

The smaller blood vessels below the knee are more difficult to treat due to their size (3mm) and are more prone to reclog than larger vessels, according to SIR.

“This study shows that with angioplasty and stenting, we can restore blood flow through the smallest vessels in the legs and keep them open long-term, saving these patients from life-altering amputation,” said lead author Nael Saad, MD, interventional radiologist at the University of Rochester Medical Center (Rochester, New York). “Aggressive interventional therapy should be considered in all patients as a first option. In general, the long-term clinical results are comparable to by-pass surgery in the leg using a longer, more complex graft, but with a much lower risk of morbidity and mortality.”

Harvey Wiener, DO, chairman of SIR’s “Legs for Life” program focused on PAD, said that Saad’s study, which he described as “objective, data-backed research,” provides information that was both previously known and that which is new.

“Dr. Saad brings out something that we’ve known about for years, which is that if we can improve blood flow to the legs, we can hopefully stave off the amputation [in cases of PAD],” Wiener told Medical Device Daily. “However, as the devices have been more refined, we’ve been able to use smaller balloons in terms of their profiles, and also stents are both smaller and more durable.”

The fact that stents are more durable means the benefits of such treatment should last longer.

In the study, 47 patients had 81 blockages treated that were below the knee; 66% were men with a mean age of 73. The patients had various risk factors indicative of PAD: 85% smoking history; 62% cardiac history; 91% hypertensive; 55% diabetic; 53% kidney disease; 53% obese; 60% hyperlipidemia.

Primary patency using angioplasty and/or stenting was 75% at three months and 55% at 18 months. By re-treating the artery that became re-clogged, the artery remained open, saving the limb in 91% at 18 months follow-up.

“What we’re doing based on this study is maintaining a quality of life,” Wiener said, noting that, otherwise, patients might be wheelchair-bound or have a prosthetic limb. “They maintain their extremities and hopefully will get onto a health and exercise program that will improve their general health.”

Wiener said this procedure should “absolutely” become the standard of care.

To perform the procedure, using imaging for guidance, the interventional radiologist threads a catheter through the femoral artery in the groin to the blocked artery in the legs. He then inflates a balloon to open the blood vessel where it is narrowed or blocked. In some cases, this is held open with a stent, a tiny metal cylinder.

This is a minimally invasive treatment that does not require surgery — “just a nick in the skin the size of a pencil tip,” according to SIR.

In general, balloon angioplasty and stenting has replaced invasive surgery as the first-line treatment for PAD.

In another study from the meeting:

A new interventional radiology technique “safely and effectively” removes blood clots in the body faster, reducing patient risk for pulmonary embolism and disability, according to SIR.

The treatment also was shown to have a positive impact on patients’ quality of life, relieving symptoms such as pain and swelling, as well as greatly improving their ability to be active.

The technique, called “rapid lysis,” combines a clot-dissolving drug with a clot-removal device, thus improving the breaking up and dissolving of the clot, which is then vacuumed out of the vein and into the catheter, non-surgically clearing away the deep vein thrombosis (DVT). Blood flow is restored throughout the leg, resolving symptoms.

Patients in the study had extensive, large-volume DVT running the length of the leg from the ankle to the pelvis, and often into the vena cava. Although the body may eventually dissolve clots, in the time needed to do so permanent damage to the vein may occur, causing permanent disability and pain.

In addition, previous studies have shown that clots in the larger veins will rarely clear on their own, SIR said.

In the study, 102 patients (62% male and 38% female) with a mean age of 47 were treated for 118 cases of large volume DVT. Of those, 51% had complete clot removal as well as restoration of blood flow. Thirty-one percent of the patients had a substantial amount, or 59%, of the clot removed with blood flow restored; 11% had partial and 4% had minimal clot removal; and 43% of patients were completed at the initial setting and did not need further infusion of medicine to dissolve clot.

Follow-up ultrasound exams at six months showed 78% of veins to be open with no DVT and 83% open at 12 months with no DVT.

The quality-of-life survey, up to one year, showed that since treatment, 68% had no pain, 67% had no more swelling and 78% no longer had heat or burning discomfort.